package com.gimi.cloud.bbp.common.utils;

import java.io.UnsupportedEncodingException;

/**
 * Base64加密类
 * @author Administrator
 *
 */
public class Base64Encrypt {

	/**
	 * 测试方法
	 * @param str
	 */
	public static void main(String str[]){
		try {
			String src = Base64Encrypt.encode("fd测试=-0987654!@#$%^&*()_+1234567890-=safdafd".getBytes());
			System.out.println(src);
			System.out.println(new String(Base64Encrypt.decode(src)));
//			System.out.println(base64EncodeChars.length);
//			System.out.println((int)"A".charAt(0));
//			for(int j = 0; j<temp.length; j++){
//				temp[j] = -1;
//			}
			
//			for(int i = 0; i < base64EncodeChars2.length; i++){
//				char s = base64EncodeChars2[i];
//				//System.out.print(s+"=");
//				//System.out.print((int)s);
//				//System.out.print("=");
//				temp[(int)s] = (byte)i;
////				byte b = base64DecodeChars[(int)s];
//			}
//			
//			for(int j = 0; j<temp.length; j++){
//				System.out.print(temp[j] + ", ");
//				if(j % 16 == 15){
//					System.out.println();
//				}
//			}
			
//			
//			System.out.println(base64DecodeChars.length);
		} catch (Exception e) {
		
		}
	}
    
//    private static byte[] temp = new byte[128];
    
	/**Base64编码数组*/
    private static char[] base64EncodeChars = new char[] {
        'Q', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
        'R', 'J', 'K', 'T', 'U', 'N', 'W', 'P',
        'A', 'I', 'S', 'L', 'M', 'V', 'O', 'X',
        'Y', 'Z', 'a', 'b', 'k', 'd', 't', 'f',
        'g', 'h', 'i', 'j', 'c', 'l', 'm', 'n',
        'o', 'p', 'q', 'r', 's', 'u', 'e', 'v',
        'w', 'x', 'y', 'z', '9', '1', '6', '5',
        '4', '3', '2', '7', '8', '0', '+', '/' };
    
    /**Base64解码数组*/
    private static byte[] base64DecodeChars = new byte[] {
    	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
    	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
    	-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 
    	61, 53, 58, 57, 56, 55, 54, 59, 60, 52, -1, -1, -1, -1, -1, -1, 
    	-1, 16, 1, 2, 3, 4, 5, 6, 7, 17, 9, 10, 19, 20, 13, 22, 
    	15, 0, 8, 18, 11, 12, 21, 14, 23, 24, 25, -1, -1, -1, -1, -1, 
    	-1, 26, 27, 36, 29, 46, 31, 32, 33, 34, 35, 28, 37, 38, 39, 40, 
    	41, 42, 43, 44, 30, 45, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1};
    /**
     * 将data的字节数组进行Base64编码
     * @param data
     * @return
     */
    public static String encode(byte[] data) {
        StringBuffer sb = new StringBuffer();
        int len = data.length;
        int i = 0;
        int b1, b2, b3;
        while (i < len) {
            b1 = data[i++] & 0xff;
            if (i == len)
            {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
                sb.append("==");
                break;
            }
            b2 = data[i++] & 0xff;
            if (i == len)
            {
                sb.append(base64EncodeChars[b1 >>> 2]);
                sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
                sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
                sb.append("=");
                break;
            }
            b3 = data[i++] & 0xff;
            sb.append(base64EncodeChars[b1 >>> 2]);
            sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
            sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
            sb.append(base64EncodeChars[b3 & 0x3f]);
        }
        return sb.toString();
    }
    /**
     * 将字符串进行Base64解码
     * @param str
     * @return
     * @throws UnsupportedEncodingException
     */
    public static byte[] decode(String str) throws UnsupportedEncodingException {
        StringBuffer sb = new StringBuffer();
        byte[] data = str.getBytes("US-ASCII");
        int len = data.length;
        int i = 0;
        int b1, b2, b3, b4;
        while (i < len) {
            /* b1 */
            do {
                b1 = base64DecodeChars[data[i++]];
            } while (i < len && b1 == -1);
            if (b1 == -1) break;
            /* b2 */
            do {
                b2 = base64DecodeChars[data[i++]];
            } while (i < len && b2 == -1);
            if (b2 == -1) break;
            sb.append((char)((b1 << 2) | ((b2 & 0x30) >>> 4)));
            /* b3 */
            do {
                b3 = data[i++];
                if (b3 == 61) return sb.toString().getBytes("iso8859-1");
                b3 = base64DecodeChars[b3];
            } while (i < len && b3 == -1);
            if (b3 == -1) break;
            sb.append((char)(((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));
            /* b4 */
            do {
                b4 = data[i++];
                if (b4 == 61) return sb.toString().getBytes("iso8859-1");
                b4 = base64DecodeChars[b4];
            } while (i < len && b4 == -1);
            if (b4 == -1) break;
            sb.append((char)(((b3 & 0x03) << 6) | b4));
        }
        return sb.toString().getBytes("iso8859-1");
    }
}
